Q1: Oral Presentation C Friday, 8:30 � 9:00 am C French River Room

Assessing the Probability of Impact of Petroleum Release Sites on Community Wells: Rochester, Minnesota

Steve Bruggeman
Maier Engineering
2125 Upper 55th Street East
Inver Grove Heights, MN  55077
sbruggeman@maier-eng.com

Sandeep Burman
Minnesota Pollution Control Agency
18 Wood Lake Drive Southeast
Rochester, MN  55904

David McConville
St. Mary�s University of Minnesota
Resource Analysis Program #16
700 Terrace Heights
Winona, MN  55987
 

An analysis of the Rochester areas was conducted in order to understand which community wells were the most vulnerable to contamination from petroleum sources. Analysis involved the development of five modules: Leaksite Proximity to Community Wells, Groundwater Flow Direction, Pollution Sensitivity of Leaksite Locations, Community Well Characteristics, and Leaksite Conditions. Each of these modules were scored on independent criteria and were then multiplied times each other to obtain the final results. In addition to obtaining a community well vulnerability reading, other information was gained from the study by using different modules in different combinations. Combining the first three modules provide a predictive way to look at areas of the community that are likely to remain problematic and might be considered for special zoning. A quick assessment of the possible impact of a new leak, spill, or point source can be obtained by looking at their locations on a grid of the values obtained by combining the first four modules. Combining the first three modules and the fifth can serve to guide new well placement, pumping rates for new wells and well testing. Areas identified with the highest probability of risk for petroleum contamination were found in the central to southern parts of the city. These areas stretch along South Broadway (Highway 63) and about two miles west and one mile east of the intersection of Broadway and Highway 14. Areas to the north and west presented the least amount of risk.